What does the construction tradeskill allow a character to do?

The construction tradeskill allows a character to build camps that apply a stacking buff to your party, as well as provide supply merchants, mail boxes, vaults, and activity areas that can be placed in world by players. Staying in range of the camp for several minutes will make the buff effect stronger.

Since patch 1.9 players will now be able to craft buildings for placement in Progress Towns. The type of building includes: Merchant, Storage, Auction, Bunkers and several others.